The study, published in Science Translational Medicine, found that a drug called MSDC-0160 helped reduce inflammation, improve motor function and maintain dopamine production in worm and mouse models of Parkinson's.
Fewer side effects
The new drug, originally developed to treat type 2 diabetes, also has fewer side effects compared to similar diabetes drugs which have shown potential for treating Parkinson's.
Previous studies of a type of diabetes drug called glitazones suggest that people with diabetes who take this type of medication are 29% less likely to develop Parkinson's than those who take other diabetes drugs.
MSDC-0160 is a new type of glitazone and seems to have fewer side effects than older drugs of this type.
Swift clinical trials
Because MSDC-0160 has already been tested in people with diabetes and Alzheimer's and been shown to be safe, it should be able to move swiftly into testing in people with Parkinson's.
Claire Bale, Head of Research Communications and Engagement at Parkinson's UK, said:
"To date no treatment has been found which can either stop or slow down the advancement of Parkinson's.
"Although it has so far only been tested in mice and worm models, the MSDC-0160 drug shows significant promise - indicating improvements in motor function, maintaining dopamine production and protecting the cells in a number of models of the condition.
"While other diabetes drugs have shown promise in Parkinson's, they can have serious side effects. Encouragingly, this new drug appears to have a better safety profile.
"This drug potentially has protective properties, which means it is likely to work best in people in the earliest stages of the condition. It is essential that clinical trials are geared towards people at this stage of the condition, to give them the greatest chance of success."